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iwd
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core: Add the preliminary logic to parse 802.11 MPDUs 

It currently focuses on parsing management frames, and specifically its
authentication and deauthentication frames.
This commit is contained in:
Tomasz Bursztyka 2014-12-12 12:17:43 +02:00 committed by Denis Kenzior
parent dd47f485af
commit 805619fc9d
3 changed files with 264 additions and 0 deletions
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1
Makefile.am
View File

@ -48,6 +48,7 @@ src_iwd_SOURCES = src/main.c linux/nl80211.h linux/kdbus.h \
src/dbus.h src/dbus.c \
src/manager.h src/manager.c \
src/crypto.h src/crypto.c \
src/mpdu.h src/mpdu.c \
iwd.h
src_iwd_LDADD = ell/libell-internal.la

166
src/mpdu.c Normal file
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@ -0,0 +1,166 @@
/*
*
* Wireless daemon for Linux
*
* Copyright (C) 2014 Intel Corporation. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <ell/ell.h>
#include "mpdu.h"
static inline bool next_byte(const unsigned char *mpdu, int len,
int *offset, unsigned char *holder)
{
if (len == *offset)
return false;
*holder = mpdu[*offset];
*offset = *offset + 1;
return true;
}
static inline bool next_2bytes(const unsigned char *mpdu, int len,
int *offset, uint16_t *holder)
{
if (len == *offset || len < *offset + 2)
return false;
*holder = L_LE16_TO_CPU(*((uint16_t *) mpdu+*offset));
*offset = *offset + 2;
return true;
}
static inline bool next_data(const unsigned char *mpdu, int len,
int *offset, unsigned char *holder, int t_len)
{
int i;
if (len == *offset || len < *offset + t_len)
return false;
for (i = 0; i < t_len; i++)
holder[i] = mpdu[*offset+i];
*offset += t_len;
return true;
}
static bool decode_mgmt_header(const unsigned char *mpdu, int len,
int *offset, struct mpdu *out)
{
if (!next_2bytes(mpdu, len, offset, &out->mgmt_hdr.duration))
return false;
if (!next_data(mpdu, len, offset, out->mgmt_hdr.address_1, 6))
return false;
if (!next_data(mpdu, len, offset, out->mgmt_hdr.address_2, 6))
return false;
if (!next_data(mpdu, len, offset, out->mgmt_hdr.address_3, 6))
return false;
if (!next_2bytes(mpdu, len, offset, &out->mgmt_hdr.sequence_control))
return false;
if (out->fc.order)
*offset += sizeof(uint32_t); /* Skipping ht_control for now */
return true;
}
static bool decode_authentication_mgmt_mpdu(const unsigned char *mpdu,
int len, int *offset, struct mpdu *out)
{
if (!next_2bytes(mpdu, len, offset, &out->auth.algorithm))
return false;
if (!next_2bytes(mpdu, len, offset, &out->auth.transaction_sequence))
return false;
if (!next_2bytes(mpdu, len, offset, &out->auth.status))
return false;
if (out->auth.algorithm == MPDU_AUTH_ALGO_SK) {
if (out->auth.transaction_sequence < 2 &&
out->auth.transaction_sequence > 3)
return true;
if (!next_byte(mpdu, len, offset,
&out->auth.challenge_text_len))
return false;
if (!next_data(mpdu, len, offset, out->auth.challenge_text,
out->auth.challenge_text_len))
return false;
}
return true;
}
static bool decode_deauthentication_mgmt_mpdu(const unsigned char *mpdu,
int len, int *offset, struct mpdu *out)
{
return next_2bytes(mpdu, len, offset, &out->deauth.reason_code);
}
static bool decode_mgmt_mpdu(const unsigned char *mpdu, int len,
int *offset, struct mpdu *out)
{
if (!decode_mgmt_header(mpdu, len, offset, out))
return false;
switch (out->fc.subtype) {
case MPDU_MGMT_TYPE_AUTHENTICATION:
return decode_authentication_mgmt_mpdu(mpdu, len, offset, out);
case MPDU_MGMT_TYPE_DEAUTHENTICATION:
return decode_deauthentication_mgmt_mpdu(mpdu, len, offset, out);
default:
return false;
}
return true;
}
bool mpdu_decode(const unsigned char *mpdu, int len, struct mpdu *out)
{
int offset = 0;
if (!mpdu || !out)
return false;
if (!next_2bytes(mpdu, len, &offset, &out->fc.content))
return false;
switch (out->fc.type) {
case MPDU_TYPE_MANAGEMENT:
return decode_mgmt_mpdu(mpdu, len, &offset, out);
default:
return false;
}
return true;
}

97
src/mpdu.h Normal file
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@ -0,0 +1,97 @@
/*
*
* Wireless daemon for Linux
*
* Copyright (C) 2014 Intel Corporation. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <stdint.h>
#include <stdbool.h>
enum mpdu_type {
MPDU_TYPE_MANAGEMENT = 0,
};
enum mpdu_mgmt_type {
MPDU_MGMT_TYPE_AUTHENTICATION = 0xB,
MPDU_MGMT_TYPE_DEAUTHENTICATION = 0xC,
};
enum mpdu_authentication_algorithm_number {
MPDU_AUTH_ALGO_OPEN = 0,
MPDU_AUTH_ALGO_SK,
};
struct mpdu_fc {
union {
struct {
uint16_t protocol_version:2;
uint16_t type:2;
uint16_t subtype:4;
uint16_t to_ds:1;
uint16_t from_ds:1;
uint16_t more_fragments:1;
uint16_t retry:1;
uint16_t power_mgmt:1;
uint16_t more_data:1;
uint16_t protected_frame:1;
uint16_t order:1;
};
uint16_t content;
};
};
struct mpdu_mgmt_header {
uint16_t duration;
unsigned char address_1[6];
unsigned char address_2[6];
unsigned char address_3[6];
union {
struct {
uint16_t fragment_number:4;
uint16_t sequence_number:12;
};
uint16_t sequence_control;
};
uint32_t ht_control; /* ToDo? */
};
struct mpdu_authentication {
uint16_t algorithm;
uint16_t transaction_sequence;
uint16_t status;
uint8_t challenge_text_len;
unsigned char challenge_text[253];
/* ToDo: FT and SAE parts? */
};
struct mpdu_deauthentication {
uint16_t reason_code;
/* ToDo: Vendor specific IE? MME? */
};
struct mpdu {
struct mpdu_fc fc;
struct mpdu_mgmt_header mgmt_hdr;
union {
struct mpdu_authentication auth;
struct mpdu_deauthentication deauth;
};
};
bool mpdu_decode(const unsigned char *mpdu, int len, struct mpdu *out);